Apparatus for the generation of driving gases by explosion and process for operating the same



June 9; 1956 A. H. SCHlLLi NG 2,750,735 APPARATUS FOR THE GENERATION OFDRIVING GASES BY EXPLOSION AND PROCESS FOR OPERATING THE SAME Filed Dec.24, 1951 5 Sheets-Sheet 1 IN V EN TOR.

Au 1152, H. Schz'l/in BY g g ATTORNEY June 19, 1956 A, H, SCHILLING2,750,735

APPARATUS FOR THE GENERATION OF DRIVING GASES BY EXPLOSION AND PRGCESSFOR OPERATING THE SAME Filed Dec. 24, 1951 5 Sheets-Sheet 2 7920c Fig. 264 I A V A 0.0595 00595 I-- 00595 0.0595 sec. Expansion I Expansion]!ScaMC/zary/hg ZqnExp/osion INV EN TOR. August H. Schilling k uw ATTORNEYJun 19-, 1956 A. H. SCHILL APPA TU R 1wv GE T EX L S AND PRQC F ING2,750,735 NERA ION OF DRIVING GASES BY ESS OR OPERATING THE SAME 5Sheets-Sheet 3 Filed Dec, 34, 1951 E 7 mm H Real/11m 3 UP: I 6 N :21.

V INVENTOR. A ugusa H Jcfizl/Phg ATTORNEY 6 Wm WM 9m Y e h SS $5 A G J n1955 A. H. SCHILLING APPARATUS FOR THE GENERATION 0F DRIVING EXPLOSIONAND PROCESS FOR OPERATING THE SAME Filed Dec. 24, 1951 INVEN TOR. AugustH. Schilling ATTORNEY June 19, 1956 H, SCHILLING 2,750,735 APPARATUS FORTHE GENERATION OF DRIVING GASES BY EXPLOSION AND PROCESS FOR OPERATINGTHE SAME Filed Dec 24, 1951 5 Sheets-Sheet 5 IN V EN TOR. A ugust HSchilling Y A 77 ORNE Y United States Patent APPARATUS FOR THEGENERATION OF DRIVING GASES BY EXPLOSION AND PROCESS FOR OP- ERATING THESAME August H. Schilling, Atherton, Califi, assignor to Schilling EstateCompany, San Francisco, Calif., a corporation of California ApplicationDecember 24, 1951, Serial No. 263,113

Claims. (Cl. Gil-39.02)

The present invention relates generally to explosion gas turbine powerplants, and more particularly to a process and apparatus for generatingpressure gases by combustion under constant volume for use in turbinesand other machines and devices driven or operated by hot gases underpressure.

It is known to generate driving gases of high temperature and pressureunder constant volume and then discharge the gases through nozzles andutilize their energy for driving a gas turbine. Theoretically, theexplosion gases produced under constant volume are capable of yieldingconsiderably larger amounts of available energy for conversion intomechanical work than gases generated by combustion under constantpressure. However, in actual practice, difficulties arose from thepeculiar character of the gas discharge from the constant volumeexplosion chambers. This discharge during each cycle was attended by asharp drop in the gas pressure in advance of the nozzles, with resultantvariations of temperature in advance of the nozzles, causing widelyfluctuating energy or enthalpy drops in the turbine from the moment thatthe discharge or nozzle valve was opened to the moment of closing. Animmediately recognizable efiect of this variation in enthalpy dropthrough the turbine was the wide fluctuation in the velocity of thegases discharging through the nozzles during each cycle. Becausevelocity turbines are designed for most efficient operation within arather limited range of gas velocities, and because the velocityfluctuations of the gases extended much beyond such optimum range, theefficiency of the velocity turbine suffered correspondingly.

In the further development of the explosion turbine, the charging andhence the explosion pressures were increased, and the total enthalpydrop of the gases was divided between two or more turbine stages. Inthese known arrangements, the total volume of live gases (of a pressureabove the charging pressure) generated by each explosion in theindividual explosion chambers was passed through each of the pluralityof turbine stages in succession. However, the use of a plurality ofturbine stages still failed to raise the individual rotor efficienciesto the desired degree.

The effort was also made to improve the rotor efliciency of the secondand subsequent turbines by equalizing the pressure of the gasesexhausting from the first turbine, and to increase the overallefficiency by utilizing the more efficient multi-stage reaction orParsons turbine as against the velocity or Curtis rotor. To this end, apressure equalizer was arranged between the first and second turbines.However, equalizers of reasonable dimensions failed to keep the pressureas uniform as was desired. In fact, equalization of the counterpressuretended to decrease the effic-iency of the first turbine by increasingthe enthalpy drop differential between the first and last portions of agas discharge.

It is accordingly the general object of the present invention to providean improved process and apparatus for realizing on the practical planethe theoretically higher efficiencies which are possible with explosionturbine Patented June 19, 1956 plants as compared with constant pressurecombustion turbine plants, regardless of whether the total availableenergy of the explosion gases is all utilized in an integrated turbineplant, or part of the energy is used in what may be called a gasgenerator plant and the remainder in another plant.

More specifically, it is an object of the invention to provide animproved method and apparatus for the utilization of high pressurecombustion gases generated under constant volume whereby the energy orenthalpy drop in one or more velocity turbines is maintainedsubstantially constant so that high rotor efiiciencies are obtained.

It is a further object of the invention to provide an improved methodand apparatus for utilizing combustion gases generated under constantvolume wherein the counterpressure acting on a rotor or on each of aseries of rotors, is controlled by the discharge of live combustiongases into the exhaust space of the rotor or rotors directly from one ormore explosion chambers, whereby substantially constant pressure andenthalpy drops in each rotor are secured, the expression live gasesherein indicating explosion gases of a pressure above the chargingpressure of the explosion chambers and prior to their performing work ina rotor.

It is also an object of the invention to provide an explosion turbineplant capable of delivering combustion gases under pressure to a placeof use and characterized by greater compactness, reduced weight andlower costs as compared with prior explosion turbine plants.

A still further object is to provide an explosion turbine plant usefulparticularly for the drive of land, sea and air vehicles which is devoidof the usual heat exchangers for converting into useful form the wasteheat of the plant, such as the cooling heat withdrawn from various partsof the plant, or the sensible heat contained in the pressure gasesdelivered by the plant, while yet providing a plant having asatisfactory degree of efficiency.

Still another and important object of the invention is so to interrelatethe individual sections of the cycle of each of the explosion chambersand the number of explosion chambers, that continuous impingement of therotor or rotors is obtained, while simultaneously providing for therapid periodic increase of the counterpressures acting on each of therotors, followed by an expansion in each case which, in the Q-V diagram(whose ordinates represent the heat content Q of the combustion gases inkcal./nm. and whose absci-ssae correspond to the percentage portions ofthe outflowing combustion gas mass or weight based on the total gas masscyclically generated in each explosion chamber), substantially parallelsthat in the anterior nozzle and rotor assembly, whereby substantiallyuniform enthalpy drops are obtained, while, preferably, the demand onthe compressor supplying compressed air to the explosion chambers is atthe same time maintained substantially continuous and uniform.

Still another object of the invention is to provide a pressurecombustion gas generating apparatus and meth- 0d of operating the same,wherein the efficiency is increased by the afore-mentioned measures tosuch a degree that, particularly in the case of power plants forvehicles of various kinds, the heretofore employed bulky and heavy heatexchange apparatus for utilizing the Waste heat of the plant and/ orexcessive heat of the gases can be eliminated without impairing thecommercial practicability of the gas generating apparatus or of theintegrated turbine plant which utilizes also the gases delivered by thegas generating apparatus.

Other objects and advantages of the invention will be apparent from thefollowing detailed description thereof and the features of novelty willbe set out in the appended claims.

The present invention provides a new and improved w construction andmode of operation of driving gas generators for the production ofcombustion gases by explosion with conversion of the combustion gasdrops at increased efficiency in a plurality of nozzle and bladingaggregates or arrangements without intermediate equalization of pressureand, in fact, with deliberately produced but controlled fluctuation ofpressure intermediately of the turbine stages, and 'f desired, alsoafter the last stage. According to the invention, generators ofcombustion gases of high pressure are constructed and operated in suchmanner that pressure equalization between turbine stages is eliminatedand instead there is produced a gradient (in the Q,-V diagram) for thegases in the exhaust space of a turbine stage which is substantiallyparallel to the gradient of the gases admitted to such turbine stage. Asa result, the gas velocity fluctuations in a turbine stage whosecounterpressure is controlled in this manner are kept within a narrowrange which the rotor can utilize with high efiiciency.

The invention is carried out by causing the counterpressure actingbehind a blading arrangement (viewed in the direction of gas flow)quickly to rise to, and then to fall from, a controlled maximum in apredetermined manner during or approximately during the period ofexpansion of the gases in such nozzle and blading arrangement, whereby aconstant or practically constant combustion gas or enthalpy drop occursin the blading arrangement under consideration. The deliberate andplanned fall of the counterpressure during or approximately during theexpansion of the combustion gases in the anterior nozzle and bladingassembly occurs in particular in such manner that the line ofcounterpressure in the QV diagram ap pears as more or less continuouslyequidistant or approximately equidistant from the expansion line. Theinvention accordingly contemplates causing the pressures in the exhaustspace following any nozzle and turbine aggregate (either of a drivinggas generator, which is designed to deliver pressure gases to anotherplant, or of a complete or integrated gas turbine power plant), topulsate rhythmically with the charges of gases delivered to suchaggregate and in such manner that in the Q-V diagram the expansion lineand the counterpressurc line have the same or nearly the sameinclination or curvature.

The control of the counterpressure or counterpressures can be effectedin various ways. Thus, a piston mechanism can be connected to thecounterpressure spaces lying behind the blading, so that, after aninitial, rapid pressure stroke, the counterpressure is reduced by aregulated outward or suction stroke. More simple, however, is thecontrol of the counterpressure through the expansion of lower pressuregases charged into the counterpressure space from one explosion chambersynchronously with the expansion of the higher pressure gases fromanother explosion chamber in the nozzle and blading arrangement. Suchlower pressure gases are available in multichamber explosion turbineplants in the form of live combustion gases, so that use can heresuitably be made of these gases for causing the rapid initial rise whichis followed by the synchronous fall of the counterpressure, as explainedin detail hereinafter.

In a further development of the invention, the process is characterizedby subdivision of the working cycle of each explosion chamber into anumber of working cycle sections corresponding to the number ofexplosion chambers. These working cycle sections are preferably arrangedin continuous series, that is, without any time pauses between them, andsubstantially without any time overlapping among the chambers; in otherWords, the working cycle sections are preferably all of substantiallythe same duration. If now the working cycle sequences of the explosionchambers of the driving gas generator are displaced progressively re a hs e t each o h r b he d ation of a working cycle section, then thereresults a particularly favorable mode of operation in that the result isobtained that at least one chamber at each operating instant chargesexplosion gases into the associated nozzle and blading system, and inthis manner a pause-free impingement can be realized.

The process of the present invention makes it possible for the firsttime to utilize efliciently impulse wheels With a single ring of bladingin explosion turbine plants. Heretofore, it was necessary to employrotors in the form of Curtis wheels with two rings of blades, so thatfixed guiding or reversing blades had to be provided which, because ofthe absence of the pauses between impingements which every rotatingblade experiences, presented difficulties in operation and constructionbecause of excessive heating. In the explosion turbine plant or gasgenerator of the present invention, however, the individual enthalpydrops in each turbine stage can be so determined that they can beutilized in single-ringed wheels whose peripheral velocities are above250 m./sec., preferably about 300 m./sec., so that rotor efficienciesbetween 75 and can be realized.

On the accompanying drawings are shown constructional embodiments of thepresent invention by way of example, with driving gas generatorsoperating with two partial expansions, the illustrated plants beingequipped with four explosion chambers. In said drawings,

Fig. 1 shows schematically a construction of an oiloperated driving gasgenerator built in accordance with the invention, the same being ahorizontal view, partly in section, and various parts being shown onlyschematically;

Fig. 2 shows the associated pressure-time diagram;

Fig. 3 illustrates the Q-V diagram of the same plant,

Fig. 4 is a Q-V diagram drawn to a different scale and illustrating amodified operation of the chambers;

Fig. 5 is a view in elevation, partly in section, of a plant similar tothat of Fig. l but showing improved forms of the charging, nozzle andoutlet valves;

Fig. 6 is a transverse section through the structure shown in Fig. 8;while Figs. 7 and 8 show schematically two modified constructionswherein the residual combustion gases are directed against a furtherturbine rotor.

Referring to Fig. 1, which shows a driving gas generating plant inaccordance with the invention, there is shown at 24 the shaft to whichthe turbine rotors 25 and 26 are fixed, the rotors each having a singlerow of blading and both forming the two turbine stages of the gasgenerating plant. The nozzle assembly I is disposed in advance of theblading 25a, such nozzle assembly being in communication with each ofthe explosion chambers, such as the chambers 27 and 28 shownschematically on the drawing, and forming part of the gas generatingplant.

The connections are shown on the drawing at 29 and 30 and are controlledby automatically operated nozzle valves 31 and 32. For the sake ofsimplicity, the control mechanism for the valves is not illustrated,such mecha nism being known. The ignition devices are shown at 5, whilethe air charging valves are indicated at 2. The turbine illustratedbeing one operated with oil, there are PI Yided fuel charging conduits,shown at 33, terminating in spray nozzles built directly into the headsof the air valves 2. An annular conduit 34 supplies the explosionchambers with charging air from a compressor plant, not shown. Specialpost-charging air valves are not provided as the explosion turbineplant, which is constructed primarily for the generation of drivinggases, is intended to operate according to the so-called open chargingprocess, described more in detail in the copending application of AugustH. Schilling and Hans Holzwarth, Ser. No. 263,114, filed December 24,1951, and entitled Apparatus for Generating Driving Gases. In such opencharging process, the outlet valve, described hereinafter, is ep p n noonl d r n h Whole p d d ri g h h.

the air charging valve is open in a chamber to efiect scavenging of thecombustion gas residue, but also during the beginning of the fuelinjection (or of a fuel gas admission where the plant is operated withgaseous fuel). With this open-chamber charging there are obtainedespecially favorable mixing conditions for the air on the one hand andfor the liquid or gaseous fuel on the other. As so far described, butexcepting the open-chamber charging process itself, the construction ofthe explosion turbine corresponds in the main to the known explosionturbine construction.

In accordance with the present invention the following additionalmeasures and features are provided:

Reference is had first to the pressure-time diagram of Fig. 2, which theabove-described turbine plant follows in known manner. In this diagram,A indicates the instant in which the highest explosion pressure hasdeveloped after the previous ignition. Upon opening of the nozzle valve31 or 32, the expansion begins, proceeding from the point A. In theabsence of the measures provided by the present invention, thisexpansion would proceed to the point C by way of the nozzle assembly I.At such point the valve under consideration closes, and one of the aircharging valves opens, and simultaneously the outlet valve opens. Therethen occurs, under the action of the incoming charging air, theexpulsion of the residual combustion gases along the line C-E. At theinstant E, the air charging inlet valve and the outlet valve close.There previously occurred at the instant D the injection of the fuel byway of the conduit 33, so that the already mentioned open charging withopen air charging and outlet valves has been realized. At the point Ethere is present in the chambers a homogeneous thoroughly mixed andignitable mixture, so that upon ignition at the instant 15 the sharppressure rise occurs which leads to the highest explosion pressure atthe point A of the next working cycle.

The above-referred to equidistant counterpressure line with respect tothe expansion line A-B is realized by the present invention and is shownat 35 in Fig. 2. Its position is determined in such manner that a seriesof further advantageous conditions is satisfied. For first of all, theaverage temperature stress of a blading system working with such acounterpressure course may not exceed the value which can reliably bemastered with known wheel constructions, rotor casings and availablemodes of cooling without causing the stresses on the materials toapproach too closely to the limiting value of the creeping strength ofthe building materials. The distance of the two equidistant diagramlines is furthermore to be so chosen, that drops arise which makepossible the use of single ringed wheels with peripheral velocitieswhich are higher than 250 m./sec., and which can, for example, amount toabout 300 m./sec. Finally, so far as possible, the counterpressure linemust run below the line of the critical counterpressure, which in thecase of combustion gases lies between 0.5 and 0.6 of the pressure in theexplosion chamber. This has the advantage that Laval nozzles can be usedin which the flow conditions in advance of the narrowest cross-section(throat) of the nozzle may with the same nozzle efficiencies be moreturbulent than with non-diverging nozzles. As the counterpressure line35 is to satisfy these advantageous assumptions, there is therebycharacterized also the narrower technical problem posed by the presentinvention. What has been said in connection with the nozzle arrangementI and the turbine wheel arrangement 25 applies also to the nozzlearrangement II and the turbine wheel arrangement 26, so that withreference to the latter a counterpressure line is to be obtained in thediagram of Fig. 2 which is characterized by the dotted line 36. v

The measures proposed by the present invention have made it .possible torealize the course for the counterpressures shown diagrammatically inFig. 2. The present invention is characterized by a deliberate andplanned cyclic variation in the pressure-time diagram of Fig. 2, of thecounterpressures 35, 36 generated behind the blade arrangements 25a,26a, viewed in the direction of flow, during or approximately during theexpansion of the combustion gases, proceeding from A, in the nozzlearrangements I, II whereby constant or practically constant combustiongas drops occur in the blading arrangement 25a, 26a, indicated by theequidistance of the expansion line proceeding from A and thecounterpressure lines 35, 36.

In order to realize constructively the invention illustrated in thepressure-time diagram, the driving gas generator according to Fig. 5 hasbeen changed in comparison with the heretofore known construction ofexplosion turbines in the following manner:

In addition to the nozzle valves, 31, 32, additional nozzle valves 37,38 (Fig. l) are provided in the explosion chambers 27, 28 which are incommunication with the nozzle pre-chambers 39, 40 by way of theconnections 41, 42. Furthermore, outlet valves 43, 44 have been providedwhich by way of the conduits 45, 46 discharge directly into the rotorspace of the turbine rotor 26, or into the corresponding exhaust housing47. The latter communicates by way of the conduit 48 with a powerturbine (not shown), which can be constructed as a multi-stage Parsonsturbine. In place of the power turbine, there can be employed any othermechanism which can utilize the pressure, temperature and/ or the heatcontent of the driving gases discharging from the exhaust housing 47.For the sake of simplicity, the cooling and insulating jackets areindicated only partially on the drawing.

As can be seen from Fig. 2, the counterpressure line 35 would reach theline of the air charging pressure p0 at a definite instant. Were thecounterpressure line to be driven further beyond this instant, that is,if the combustion gases were allowed to expand in the nozzles I beyondthe instant which corresponds to the intersection of the counterpressureline with the charging air pressure line, in order to obtain also in theinterval beginning from this intersection point on, a constant orapproximately constant combustion gas drop, then, viewed in thedirection of gas flow, there would prevail in advance of the nozzles IIa lower pressure than in the exhaust housing 47, since the latter ischarged with residual combustion gases of the pressure of the chargingair pursuant to the chosen method of charging the chambers. Back flowand braking action on the turbine rotors would therefore arise, whichare obviously undesirable. For this reason, the expansion of the gasesin the nozzles I must be interrupted at an instant which is in advanceof this point of intersection of the counterpressureline 35 with theline of the charging air pressure 10. This instant is preferablyadvanced some what with respect to the point of intersection for reasonsof safety. It is indicated in Fig. 2 at B. At the point B, therefore,the nozzle valves 31, 32 are closed and the nozzle valves 37 and 38 areopened. The latter nozzle valves close at the instant C and the outletvalves 43, 44 are opened, such latter valves being closed at the pointE.

The control phases of the valves 31, 32 or 37, 38 or 43, 44, and hencethe working cycle sequences of the explosion chambers 27, 28, etc.associated with nozzle and blading arrangements I, 25a and II, 2611, aretime-displaced with respect to each other in such manner that, duringthe time interval of the expansion ABin the nozzle and bladingarrangement I, 25a, of a combustion gas portion of higher pressure,withdrawn from the explosion chamber 28, a combustion gas portion oflower pressure withdraw from the explosion chamber 27 is utilized forcreating the initially increased and then diminishingcounterpressure,shown by line 35, in nozzle pre-chamber 39, 40; and that, during thetime interval of the expansion in the nozzle and blading arrangement II,26a of a combustion gas portion withdrawn from the explosion chamber 27,a combustion gas portion of still lower pressure withdrawn from. a thirdexplosion chamber is utilized for producing'the' initially raised andthen diminishing counterpressure 36' in the exhaustspace 47.Accordingly, the nozzle valves 32 and 37 are in the open condition,while the nozzle valves 3-1 and 38, as well as the outlet valves 43 and44, are in the closed condition; a further outlet valve (of a thirdchamber) corresponding to the outlet valves 43, 44 is to be imagined asbeing open, so that the third explosion chamber discharging thecombustion gas portion of lowest pressure during such interval is incommunication with the discharge housing 47. During the expansion A-+B(-Fig. 2) of the highest pressure combustion gas portion of the totalgas quantity generated by explosion in the explosion chamber 28 andconducted through the open nozzle valve '32 to the nozzle assembly I andthe blading 25a, the counterpressure in the nozzle pie-chambers 39, 40,which to this end are connected in a manner not shown in detail, forexample by making them of annular form, runs according to thecounterpressure line 35, corresponding to the simultaneously occurringexpansion B*C of the lower pressure gas portion of the total combustiongas mass generated in the explosion chamber 27 and introduced into thenozzle pre-chambers 39, 40 through the opened nozzle valve 37. It willaccordingly be understood that the partial expansion BC of the diagramof Fig. 2 and referred to in the preceding sentence in actuality belongsto another diagram which reproduces thepressure course in anotherchamber, such as 27, and that, therefore, the partial expansion B-C of alower pressure combustion'gas portion discharging from the explosionchamber 27 and producing the counterpressure line 35 to the partialexpansion A-B in the explosion chamber 28, does not belong to thediagram of Fig. 2 but rather to the pressure-time diagram of explosionchamber 27 which, iii-contrast to the pressure-time diagram of explosionchamber 28 shown in Fig. 2, is so advanced that during the time intervalof the partial expansion A-'B of the higher pressure combustion gasportion discharged through nozzle valve 32 from explosion chamber 28,the explosion chamber 27 is already discharging a lower pressurecombustion gas portion whose expansion line, according to its ownpressure-time diagram, is advanced by the time interval AB with respectto the diagram of Fig. 2, and lies'directly under the partial expansionline A-B. This applies correspondingly to the combustion gas portion oflowest pressure which yields the counterpressure line 36 and which inthe embodiment of the invention described expands into the exhausthousing 47 during the time interval C-E as a residual combustion gasmass expelled out of an explosion chamber by the charging air; thepressure-time diagram of this not illustrated chamber discharging theresidual combustion gases precedes the diagram of Fig. 2 of chamber 28by the time interval A-C. In other words, the course of the Workingcycles in the chamber 27 is so advanced in time with reference to thecourse of the working cycles in chamber 28, that during the productionof the counterpressure course 35 in the nozzle pre-chamber 39g 40 withthe aid of the lower pressure combustion gas portion discharging throughthe opened nozzle valve 37 into the pre-chamber 39, 40 the higherpressure combustion gas portion discharged from explosion chamber 28 byway of nozzle valve 32 is expanded along the partial expansion line A-B.Corresponding to this time-displacement of the working cycles, thecounterpressure in the exhaust housing 47 develops according to the line36 during the counterpressure course 35 in the nozzle pre-chamber 39,49. It will thus be evident that the gas discharges represented by thelines -A'-B, BC and C-E occur simultaneously from three diiterentchambers. In this way the general objective of the invention isfulfilled: the combustion gas portion conducted to the nozzle andblading system I, 25 through the opened nozzle valve 32 is utilized withapproximately uniform enthalpy drop, which is characterized by theexpansion line -A'B and the approximately equidistant counterpres'sure'line 35; the lower pressure combustion gas portion "brought into actionon the nozzle 8 and blading system II, -26 is simultaneously convertedin such nozzle and blading system with approximately uni form enthalpydrop, since the line 35,-now to be regarded as the expansion line ofthis lower pressure combustion gas portion, runs substantiallyequidistant to the counterpressure line 36 of the exhaust housing 37.

For a clearer understanding of the energy distribution and individualenthalpy drops throughout the plant, reference is had to the QV diagramshown in Fig. 3.

In this diagram, there is again'shown the course of the ordinatesproceeding from A, while the discharged com bustion gas quantities areto be read ofi on the abscissa axis. The pressure and temperature linediagram is only indicated, and again is valid only for the double lineproceeding from A. This double line represents the changes of conditionduring the expansions. These changes appears in the QS diagram asvertical adiabatic lines, but only in the ideal machine, in which nochange of entropy appears during the expansion, that is, no heat is lostto the walls and no heat is absorbed from the friction heat of therotors and blades. In the practical machine, however, both of thesephenomena occur. Careful investigations on the heat interchange at thewalls on the part of the combustion gases, and calculations of theventilation losses of the wheels and blades show that in carefullydesigned plants the methodsof operation which from the practicalstandpoint come chiefly into consideration, there is substantialequality between the heat delivered and the heat absorbed. It is,therefore, approximately correct to assume that the changes incombustion gas conditions during the expansions are adiabatic changes incondition also for the practical machine, and these appear in the Q-Sdiagram as vertical lines. There is further included the dot and-dashcounterpressure line 35 and the dotted counterpressure line 36. Theselines, in combination with the ordinates through the points B and C,determine the following areas: Ia, Ib, II and III. The area Ia below thecurve of the partial expansion A-B corresponds to the work ofthe'combustion gas portion discharging from the nozzle assembly Iexerted upon the rotor 25. The dotand-dash dividing line (35) betweenthe areas Ia and lb corresponds to the counterpressure in the nozzleprechamber 3?, 40-and thus corresponds to the counterpressure in therotor space 25. This counterpressure line is in the main dependent uponthe number of working explosion chambers, the number and size of thenozzle prechambers, and the narrowest nozzle cross-sections. The rotorefiiciency of the explosion turbine can be extensively influenced by theshape of this counterpressure line in the QV diagram. It is influencedin the most favorable way when it is possible with the measures of thepresent invention to make it run equidistant to the line A-B or nearlyso. A small deviation from the equidistant relationship must be takeninto account when the nozzle precharnbers 39, 40 are being filled withthe gases of intermediate pressure discharging through nozzle valves 37and 38, but this deviation is toosmall for it to operate unfavorably onthe efiiciency to any substantial degree.

The reference character lb designates an area which corresponds to thework of the originally higher pressure combustion gas portion in thenozzle and blading arrangement II, 26 and delivered by way of thenozzles I. The working area Ib is bounded below by a dottedcountel-pressure line 36 which corresponds to the condition of thecombustion gases in the discharge housing 47 or in the exhaust space ofrotor 26. There is also recognizable the approximate equidistancebetween the dot-and-dash counterpressure line 35 and this dotted line36, so that also those ethalpy drops are maintained approximatelyconstant to which the combustion gas portion conducted by way of thenozzle arrangement I is subjected on being caused to do Work in thesecond turbine stage.

There is also shown the working area II which corre' sponds to theavailable work which the lower pressure combustion gas .portiondischarged through one of the nozzle Valves 37, 38 develops in theturbine arrangement II, 26. Also this lower pressure combustion gasportion, in consequence of the equitlistance between the curve BC andthe dotted counterpressure line 36 along the major portion of the courseof the counterpressure line, experiences approximately uniformcombustion gas drops, so that both turbine stages convert approximatelyconstant individual drops. It thus becomes possible to utilize withoptimum efliciency a rotor or a suitable rotor group designed as far aspossible for these uniform pressure or enthalpy drop conditions, andthereby to bring the explosion turbine into the field of turbinesoperating with uniform drops. This applies also to the working area IIIof the power turbine (not shown).

Fig. 4 shows a QV diagram, drawn to scale, of a modified process inwhich more or less constant pressure combusion is combined withcombustion under constant volume. In the process forming the basis ofthe diagram of Fig. 4, combustion is initiated in close proximity to thenozzle valve 31 or 32 through which the combustion gas portion ofhighest pressure is discharged into the first or high pressure nozzleassembly. This nozzle valve is opened prior to the completion of thecombustion, that is, prior to the attainment of the maximum pressurepeak A which corresponds to the point A of the diagram of Fig. 3. Thosegases whose combustion has been more or less completed will then passout of the combustion chamber before the end of the combustion phasewhich, nevertheless, proceeds to completion. This modified process thussubstitutes for purely constant volume combustion a peak phase whereinthe combustion occurs at essentially constant pressure. By this mode ofoperation, after the gases in the completely closed combustion chamberhave attained a certain pressure, by combustion under constant volume,they are discharged through the prematurely opened nozzle valve undermore or less constant pressure which is maintained by the continuingcombustion of the gas in regions more remote from the nozzle valve.While the combustion continues, the pressure in the chamber tends toincrease slightly at first and then approaches a true, constant pressurecombustion and as the burning enters its final stage, the pressurecommences to drop. At this time, the pressure-time curve crosses andthen approaches the expansion line which is obtained on the discharge ofgases produced entirely under constant volume. The curve x in Fig. 4indicates the expansion line for the highest pressure gas portion whenthe nozzle valve is opened at the instant at which the constant volumecumbustion has produced a pressure of 50 atmospheres absolute instead ofthe 64 atmospheres absolute that can be obtained with combustioncompletely under constant volume. It will be seen that the curve x isapproximately horizontal for a very large fraction of the total volumeof gas discharged during the first expansion. It will be noted that thecurve x follows more closely the outline of the counterpressure linethan does the line AB, so that even during the very first period of thisfirst expansion, the expansion line and the counterpressure line arevery nearly equidistant. Investigation has established that despite theloss of the area above the curve x, the available energy from thiscombined constant volume and constant pressure process is practicallythe same as that of the pure expansion process. On the other hand,because of the more uniform heat drop effected by this combined process,the turbine blades can be designed for more constant conditions, andthus, with the increase in rim speed, the average wheel efiiciency israised very considerably, for example, from 70 to 76%.

Somewhat similar results can be obtained by a premature opening of thenozzle valve combined with the injection of additional fuel into thechamber while the nozzle valve is open. This process is indicated bycurve y in Fig. 4 which shows the condition of the gases after openingof the nozzle valve at the instant at which the pressure in the closedcombustion chamber has reached 42 atmospheres absolute. Upon thesupplementary injection of fuel, the gas pressure quickly rises, andthis rise is followed by an approximately horizontal peak, the curve y,like the curve x, crossing the expansion line AB and then meeting it atthe point B. This latter method increases the amount of combustiontaking place at approximately constant pressure, but while the' peakpressure is reduced, improvements in the mechanical efficiencies aremade possible.

What has been said upon the basis of the constructional example of Fig.1 for the discharge of a high-pressure combustion gas portion by way ofthe opened nozzle valve 32, for the simultaneous discharge of a lowerpressure combustion gas portion by way of the opened nozzle valve 37,and for the likewise simultaneous discharge of the combustion gasresidue from a third explosion chamber through its outlet valve, appliesin cyclical interchange for all the combustion gas portions of all ofthe chambers. Thus, for example, during the previous opening of thenozzle valve 31 of the explosion chamber 27 for discharging the higherpressure combustion gas portion, the nozzle valve 32 of the explosionchamber 28 and of the other chambers was closed, but the nozzle valve ofanother chamber, corresponding to the valves 37 and 38, was open, sothat in the nozzle pro-chamber 39, 40 (which, as already stated, can beof annular form but which can also be semi-annular or approximately so,and is fed from all of the valves 37, 38), a rapid rise followed bygradual lowering of the counterpressure occurred, which provided thatthe higher pressure combustion gas portion brought into action by Way ofthe opened nozzle valve upon the nozzle and blading system I, 25aexperienced a substantially uniform enthalpy drop in consequence of theequidistant course of the expansion and counterpressure lines. Thiscyclic interchange correspondingly applies to all the nozzle valvesdischarging the lower pressure combustion gas portions and to the outletvalves discharging the residual or lowest pressure combustion gases.

The invention is in no way limited to the two-stage turbine shown inFig. 1. The lowering of the counterpressure in the manner described cantake place even with a single stage turbine arrangement in order toproduce therein a uniform pressure drop. This applies correspondinglyfor aggregates with more than two turbine stages, and with more than twopartial expansions out of the chamber (at initial pressures above thecharging pressure); however, an increase of the average stressproducingtemperatures accompanies an increase in the number of turbine stages orpartial expansions, so that the number of partial expansions which canbe realized in a practical plant is limited by the availability ofsuitable building materials.

In addition to the pressure, the temperature and heat content of thecombustion gases are also controlling for the combustion gas conditionwhich results in a definite enthalpy drop with reference to anothercondition. It would therefore be theoretically possible to effect thelowering of the drop limiting lines 35 and 36 in Fig. 3 without alteringthe pressure of the combustion gases, that is, the counterpressure, inrelation to an anteriorly arranged nozzle and blading sysem. As in thisway the essence of the invention would not be departed from, theexpression, counterpressure is to be understood in this further sense ofthe line in the QV diagram corresponding to this counterpressure.

' According to a further feature of the invention, the number ofchambers is related to the number of partial expansions insuch mannerthat continuous impingement of the rotor is obtained while at the sametime the ob tainment of the above-described substantially uniformenthalpy drop-producing counterpressure lines is insured. Despite thefact that the individual procedures or phases of a chamber cycle developpartially according to physical and chemical laws as, for example, thedura tion of the explosion-like combustion, it is possible by thecontrol of the explosion chamber and through the at first arbitraryfixing of the control instants to impart to the working cycle sectionsthemselves a definie time inerval and to determine at will theirposition in relation to the whole working cycle, considered from thetime standpoint. Thus, with reference to the duration of the explosion,it is necessary only to adjust the mo ment of termination of thechanging of the explosion chamber with an ignitable mixture in suchmanner that up to the opening of the nozzle valve which discharges thecombustion gases of highest pressure, there elapses a time intervalwhich is greater than the time interval between the ignition and thedevelopment of the highest explosion pressure or the selected pressureat which the valve is to be prematurely opened, taking into account theignition delay and other factors bearing on this time interval.

Considering the working cycle sections in detail, it will be evidentthat three working cycle sections play especially important roles in theoperation of explosion chambers. Assuming a completely evacuatedchamber, such as exists only on first setting a driving gas generatorinto operation, there is first to be produced in this chamber anignitabie mixture. To this end there are available a great variety ofpossibilities, among which that charging process is to be preferredwhich involves the shortest charging periods, so that maximum workingcycle frequencies can be attained. This is possible only when theworking cycle sections develop in the theoretically and practicallyshortest times. Such a charging process is characterized by the factthat at the beginning of the charging cycle section, the air inlet andresidual combustion gas outlet members of the explosion chamber areopened and that both members are closed at the end of such working cyclesection. After the discharge of the high pressure explosion gases thereremain behind in the chamber residual combustion gases which are at thecounterpressure existing at the time of closing of the nozzle valve,which residual gases must be removed to prepare the chamber for thereception of the new charge; in other words, the chamber must bescavenged. If the residual combustion gases are displaced by theentering charging air itself, the period of preparation of the chamberfor the new charge is reduced to the charging period itself, that is, tothe time interval during which the charging air must be admitted inorder that at the instant of ignition the chamber may be filledcompletely with an ignitable mixture. For the same reason, the fuel isintroduced during a time interval which extends over a portion of thetime allotted for the air charging, particularly by the injection of aliquid fuel. Thereby the advantage arises that the charging air which isstill in motion seizes the fuel and distributes it uniformly over thewhole length of the chamber.

Upon the charging cycle section just considered there follows thelikewise important section which includes the ignition and explosivecombustion. This section is characterized, in a further development ofthe invention, by the fact that at the beginning thereof the chargingair inlet and residual combustion gas outlet members are closed, whileat its termination a nozzle valve is opened for combustion gases whichare initially at the maximum explosion pressure.

Taking into account the two basic working cycle sections of charging(with scavenging), and ignition (with explosion), the total number ofcycle sections in my preferred mode of operation is n+2, wherein n isthe number of partial expansions (with initial pressures above chargingpressure). Accordingly, the number of chambers is likewise n+2, However,the invention is not restricted to a process involving only two nonexpansion cycle sections or phases. Thus, separate working cyclesections can, for example, be provided for the residual gas displacementat any instant of operation.

12 (scavenging) and for the charging with a combustible mixture. In suchcase, and with the use of two partial expansions, there would result, inall, five cycle sections of equal duration for whose development fivechambers would be required with cyclic displacement of the chambers eachby a working cycle section. If the expansion is not subdivided, thenfour cycle section processes will arise, for whose development fourchambers are required. On the other hand, it is possible to compress theresidual combustion gas displacement, charging, ignition andexplosioninto a single working cycle section and to provide at least onefurther working cycle section for the expansion. However, this mode ofoperation becomes restricted to lower cycle numbers per unit of time;also, certain reactions upon the charging air supply cannot be avoided.

When it was stated above that the invention contemplat-es a subdivisionof the working cycle into a number of working cycle sectionscorresponding to the number 'of explosion chambers, it is to beunderstood that in the calculation of the number of explosion chambersonly those explosion chambers are to be counted which, corresponding tothe time displacement of the working cycles by a working cycle section,develop working cycle sections which vary from one another, that is, areout of phase, t is naturally also possible, as for limiting the chambersize, to provide parallel-operating chambers, that is, chamber groups,which in relation to the cyclic displacement of the working cyclesbehave no differently from a single large chamber and thus belong in thesame working cycle section. In such case, in counting the explosionchambers, the number of groups of chambers is taken in place of theindividual chambers.

Figs. 5 and 6 show two views of a four-chamber explosion turbine gasgenerator operating in the manner just described and illustratingcommercially satisfactory forms of nozzle valves and associated parts.The explosion chambers operate with four working cycle sections whichfollow upon each other without gaps and without overlapping and have thesame time periods. Assuming a control shaft speed of 252 R. P. M. thereoccur 252 complete working cycles per minute, that is, the working cycleperiod amounts to 0.238 sec., so that the duration of each cycle sectionis 0.0595 sec.

In Fig. 6 there are shown four explosion chambers 62, 63, 64, and 65which are associated with nozzle and blading systems common to them. Theexplosion chamber 65 is shown in longitudinal section in Fig. 5, whilethe chamber 64 is seen in elevation. Each chamber is equipped with acharging air inlet valve 66, into which is built the fuel injectionvalve 67 to which the supply conduit 68 leads, while the charging airsupply is indicated at 69. The control mechanism for the air chargingvalves is indicated at '70. The fuel conduits 63 lead to a 4-plungerfuel pump of usual construction (not shown) or other fuel feedingmechanism. The explosion chamber itself has a Venturi nozzle-like inletend as shown at 71, the diifusor 72 being constructed with a very slighttaper so that the entering charging air spreads out in piston-likefashion and is able to push out the residual combustion gases withoutforming whirls to any substantial degree. The outlet valve for theresidual combustion gases is shown at 73. In addition to such valve,there is shown also the nozzle valve 74 which is designed to dischargethe combustion gases of maximum pressure. Fig. 6 shows at the right sidethe nozzle valves 74 associated with the explosion chambers 64 and 65.The valves 74, which are constructed as substantially unloaded pistonvalves, pass over into the nozzle pre-chamber 76 at the seat 75, thenozzles 77 being connected with such pro-chamber. The nozzles 77 arearranged in advance of the blading 78 of the rotor 79 of the firstturbine stage.

Each explosion chamber has in addition to the nozzle valve 74 a secondnozzle valve 80 whose construction is fundamentally the same as that ofvalve 74. Separate nozzles can be associated with the nozzle valves 80,as is shown in Fig. 6 for the nozzle valves 74. In the illustratedexample, however, a different construction is shown in that gas conduits81 are connected to the seats of the nozzle valves 80, the conduitsleading to a collecting chamber 82 arranged between the two turbinestages of the plant shown in the drawing. This collector chamber notonly receives combustion gases by way of the nozzle valves 80 andconduits 81, but is provided in addition with a catch nozzle assembly 83for the combustion gas portion exhausting from the first turbine stage77, 78, 79.

The collecting chamber 82 is provided at its end lying opposite to thecatch nozzle assembly 83 with an outlet nozzle assembly 84 which isarranged as impinging nozzle in advance of the blading 85 of wheel 86 ofthe second turbine stage. With the blading 85 there is associated asecond catch nozzle arrangement 87 which is in open communication by wayof conduit 88 with the mouth of the driving gas withdrawal conduit 89.Conduit members not shown in the drawing debouch at the same point andconduct the residual combustion gases to the withdrawal conduit 89,which gases are discharged through the outlet valves 73. The turbinestages 77, 78, 79 and 84, 85 and 86 transmit their mechanical output byway of the shaft 90 of rotors 79, 86 to a work-absorbing machine 91which can be constructed as a compressor for charging air and, ifrequired, also for fuel gases. The Q--V diagram of the process conductedin the apparatus of Figs. and 6 is the same as that shown in Fig. 3.

In the constructional examples of Figs. 7 and 8, the

features and advantages discussed in connection with the other figuresare essentially retained. Similar parts are designated with the samereference characters as in Figs. 5 and 6. There exists, however, thedifference that a separate nozzle and blading system 96, 97 is arrangedafter the outlet valve 73 of the constructional example according toFig. 7, whereby by the arrangement of a third wheel 98 a third turbinestage arises. The turbine stages 84, 85, 86 and 96, 97, 98 have a commonexhaust housing section 99, so that the advantages obtained with thestructures of Figs. 1, 5 and 6 with reference to the course of thecounterpressure are retained. This is also the case in theconstructional example of Fig. 8, as here in place of the common exhausthousing section 99 a collector chamber 100 is provided which by reasonof the fact that the conduit connected to the outlet valve 73 opens intoit, remains subjected to the counterpressure course indicated by theupper boundary line 36 of the whole area III in Fig. 3. Thereby thesecond turbine stage 84, 85, 86 remains subjected to a counterpressurecourse which is not essentially different from that of the exampleaccording to Figs. 5 and 6, so that the improvements which are apparentfrom Fig. 3 are retained also in the embodiment according to Fig. 8. Asin Fig. 1, the rotors in Figs. 5, 7 and 8 can be and preferably areconstructed with single rows of blades, this simplified constructionbeing favored by the fact that the explosion gases are withdrawn fromeach explosion chamber in a plurality of successive portions, so thatthe utilization of each portion involves only a relatively smallfractional enthalpy drop.

While the volume subdivision of the live explosion gases represents andat present preferred form of the invention, it will be evident that thefeature of so determining the periods of duration of the several phasesor sections of a working cycle and the number of explosion chambers (orparallel-acting explosion chamber groups) and the displacement of theworking cycles of the chambers with respect to each other that acontinous discharge of gases to the nozzle and blading systems occurs,with the result that the turbine shaft is continually under the actionof a driving torque, can be utilized without such volume subdivision.This result is independent of the manner in which the live explosiongases are discharged during each cycle, it being necessary only that thedischarge of explosion gases from one chamber begins immediately uponthe end of the discharge from another chamber. Nor is the inventionrestricted to a process in which charging of the explosion chambers withair and fuel is accompanied by simultaneous scavenging; for thescavenging step can be effected during a separate cycle section or phasepreceding the charging phase in any chamber.

It will be understood that the gases exhausting from the first turbinerotor and the gases discharged from one of the nozzle valves 37 or 38 inthe collector chamber 39, 40 enter simultaneously, so that the nozzles11 charge a mixture of such gases at their resultant pressure. In theforegoing discussion in connection with Figs. 6 and 7, these two gasportions have been treated separately only in order to be able torepresent on the diagram the amount of work performed in the secondturbine stage 26 by each of such portions. The diagram is, therefore,not neces sarily to be interpreted as indicating that these two gasportions, i. e., that exhausting from the first turbine stage and thatdischarged by a nozzle valve 37 and 38, operate in the second turbinestage independently of each other.

The shaded areas of Figs. 3 and 4, as already indicated, present ameasure of the available work which the individual gas portions are ableto deliver in the stages of the plant. While the outputs correspondingto the surfaces Ia, Ib and II are to be developed in the two stages ofthe actual explosion turbine, the area III represents the availableworking capacity of the combustion gases which enter the withdrawalconduit 48 as driving gases. Through such conduit the gases reach theultimate stage of use which can be constructed in any desired manner,such as a multi-stage Parsons turbine for driving an electric generator,a pump, or other work-absorbing machine. The driving gases can, however,also be utilized purely thermally, chemically, pneumatically, or in anydesired combinations of these possible uses.

From the ratio of the area III, which is a measure of the net output ofthe plant, to the sum of the areas Ia, Ib and II, which can be regardedas representing the work required to operate the auxiliary devices ofthe explosion turbine plant (operating as a pressure gas generator),such as the compressor, it can be seen that the plant opcrates with highefficiency. Thus, because of the high efliciency of the explosionturbine plant itself, the output of such plant, represented by the areasIa, Ib and II, suffices for driving all auxiliary machines, particularlythe charging air compressor, without its being necessary to utilize thewaste heat of the plant to aid in providing the required compressionwork. This makes it possible for the first time to realize an explosionturbine plant operating with a practical degree of efiiciency withoutthe utilization of the waste heat of the plant, including the excessheat of the delivered pressure gases or of the final exhaust gases. Thecooling agents of the plant employed for cooling the chambers, nozzles,bladings, rotors, shafts and valves are, in the simplified form of theinvention, accordingly drawn off after absorbing the cooling heatwithout utilizing the cooling heat for purposes of power generation. Asin most cases, however, special cooling agents with high boiling pointsare employed, it would be uneeonomical to withdraw such cooling agentsfrom the plant; in such case, the re-cooling apparatus is retained, butthe re-cooling agent for the cooling media is discharged afterabsorption of the re-cooling heat, such recooling agents consistinggenerally of water or air. There is likewise abandoned the utilizationof the sensible heat of the exhaust gases of the last turbine stage; theexhaust gases are discharged from the plant with their sensible heatwithout utilizing the excess heat for the purposes of the explosionturbine stage of the plant or for the drive of the auxiliary machines.Pursuant to this feature of the invention, the combustion gas conduitswithin and after the explosion turbine stages are constructed withcompletely. open cross-section; they are neither to be enlarged formaintaining uniform gas velocities as is necessary in the insertion ofheat exchangers, nor is their'open cross-section 'to be reduced by theinsertion of heat exchangers. The combustion gas conduits between'theindividual stages of the explosion turbine are all arranged inside ofthe turbine housing to which only the driving gas withdrawal conduit isattached for conducting the generated driving gases to a place of use.

From the foregoing, it will be seen that by reason of the improved modeof operation above described, increase in efficiency of the explosionturbine stage itself, i.-e., the apparatus shown in Figs. 1 and 5 to 8,is so high that the whole integrated power plant, by which term Iinclude the ultimate work-absorbing machine or the like, operates at anover-all etficiency which enables such plant to compete successfullywith other modes of generatmg power without'the necessity for utilizingthe waste heat of the plant. By'thi's elimination of the conversion ofthe waste heat of the'plant into a source of additional power, the plantis greatly simplified in construction and thereby the initial investmentcost reduced. Also, by the elimination of bulky heat exchangers, theplant has been made more compact and lighter in weight and, therefore,highly suitable for the drive of various types of vehicles.

While, in the preferred manner of carrying out the invention, all of thecycle sections are of equal duration, this is not absolutely essential,it being necessary only that the cycle sections of the partialexpansions out of the explosion chambers be of substantially equalduration, and that the duration of each such section be substantiallyequal to the total cycle period divided by the number of explosionchambers operating out of phase to insure continuous impingement.

It will be understood that the values of temperatures, pressures, cyclenumbers, rotor rim speeds, etc., specifically mentioned above, are givenonly by way of example and that the invention is not to be regarded aslimited thereto.

It will be recognized that the proper control of the various valvesforms an essential part of the above-described process and apparatus.Valve control mechanisms of hydraulic, mechanical, andhydraulic-mechanical types suitable for use with the above-describedapparatus are, however, well known. Such control devices and the timingmeans therefor have, therefore, not been illustrated, as they form nopart of the present invention. The suitable control and timing devicesare, for example, shown in United States Patents Nos. 1,756,139,1,763,154, 1,786,946, 1,933,385, 2,010,019, and 2,063,928.

Certain novel structural features shown in the drawings of thisapplication do not form part of the present inven' tion and are notclaimed herein, the same being claimed in various applications beingfiled simultaneously herewith.

I claim:

1. Process for the operation of a driving gas generator for producingcombustion gases for use externally of the generator, said generatorincluding at least one nozzle and rotor blading assembly and explosionchamber means for providing explosion gases which are charged into saidnozzle and rotor assembly, the pressure of the gases in the nozzleassembly falling as the discharge of gases from an explosion chamber threinto proceeds, said process comprising periodically raising thecounterpressure behind the blading, viewed in the direction of gas flow,and then causing the counterpressure to fall, approximately during andsynchronously with the expansion of the gases in the nozzle and bladingassembly, whereby a substantially uniform change in enthalpy occurs insaid nozzle and blading assembly.

2. Process according to claim 1, wherein the lowering of thecounterpre'ssu're is efiected by expanding the gases producing thecounterpressure synchronously with the expansion of the gases in thenozzle and bladrng assembly, and withdrawing suchcounterpressure-producing gases successively from a plurality of exploson chambers associated with the same nozzle and blading assembly andcharging the same "as live gases into the counterpres-Z sure-space.

3. Process according to claim 1, wherein the counterpressure iscontrolled by charging, into the counterpressure space, combustion gasesdischarged from an explosion chamber associated with the nozzle andblading assembly at a moment in which there appears in such chamber agas pressure corresponding approximately to the gas pressure which thegases have at the end of the expansion in the nozzle assembly.

4. Process for the operation of a driving gas generator for producingcombustion gases for use externally of thegencrator, wherein thecombustion gases are generated in a plurality of explosion chambers inwhich combustible mixtures are formed, ignited and exploded, and thendischarged, the chambers being provided with air charging valves, nozzlevalves for discharging high pressure explosion gases from the chambers,and with outlet valves for discharging the residual combustion gases,said process comprising dividing the working cycle of each explosionchamber into a number of working cycle sections corresponding to thenumber of explosion chamhers, and elfecting explosion in the chambersunder constant volume in succession.

5. Process according to claim 4, wherein the working cycle sections ofeach chamber are made to follow each other in series Without interveningtime intervals.

6. Process according to claim 4, wherein the working cycle sections ofeach chamber follow each other in series without mutual overlapping intime.

7. Process according to claim 4, wherein the working cycle sections ofeach chamber follow upon each other and are of the same duration.

8. Process according to claim 4, including the step of displacing theWorking cycle section sequence of the explosion chambers progressivelyby the duration of one working cycle section.

9. Process according to claim 4, wherein the working cycle of eachexplosion chamber is divided into at least n+2 working cycle sections,it being a whole number at least equal to l, and including the step ofsubjecting the explosion gases to expansion during a time interval whichis equal to n times the duration of a working cycle sectiomsaid n+2working cycle sections including a section for charging and scavengingan explosion chamber and at least one further section for ignition andexplosion.

10. Process according to claim 1, wherein except for unavoidableheatlosses, the balance of all the heat and pressure energy of theexplosion gases utilized in the gas generator is contained in the gasesdischarged by the generator.

11. Apparatus for the production of pressure combustion gases,comprising a plurality of explosion chambers, a nozzle and bladingassembly, a gas collecting space behind said assembly, viewed in thedirection of gas flow, a plurality of controlled valves in each of saidexplosion chambers, means connecting a valve of eachchamber with thenozzle assembly and another valve of each chamber with the collectingspace behind the blading, and means for controlling the outlets to causedischarge of live explosion gases into said space during the expansionof explosion gases in the nozzle assembly.

12. Apparatus for the production of pressure combustion gases,comprising a plurality of explosion chambers, means for charging thesame with compressed air and fuel, a nozzle and rotor assembly, each ofsaid explosion chambers having a nozzle valve for discharging theexplosion gases to said nozzle and rotor assembly, a gas collectorbehind the said assembly, viewed in the direction of gas flow, and intowhich the partially expanded gases exhaust, said explosion chambers eachhaving also a discharge valve for charging combustion gases into saidcollector, means for withdrawing gases from said collector, and meansfor operating the valves of said chamber's in time-displaced relation insuch manner that while the nozzle valve of one chamber is open, thenozzle valve of a second chamber is closed and its discharge valve isopened at an instant in which the pressure in the explosion chamber issubstantially higher than in said collector, whereby the gases in thecollector undergo a compression with subsequent expansion approximatelysimultaneously with the expansion in the nozzle assembly and asubstantially constant change in enthalpy occurs in said assembly.

13. Apparatus according to claim 12, including a second nozzle and rotorassembly receiving the gases from the collector, an exhaust chamberbehind the second nozzle and rotor assembly, said explosion chamberseach having also an outlet valve connected with said exhaust chamber,said valve operating means opening the outlet valve of a third chambersubstantially simultaneously with the opening of the discharge valve ofthe second chamber and at an instant at which the pressure in said thirdchamber is substantially higher than in the exhaust chamber, whereby acompression with subsequent gas expansion occurs in the exhaust chambersubstantially simultaneously with the expansion in the second nozzleassembly, whereby a substantially constant change in enthalpy occursalso in said second assembly.

14. A driving gas generator for producing and delivering combustiongases under pressure, comprising a plurality of explosion chambers eachprovided with compressed air and fuel charging valves, with at least onenozzle valve for the discharge of high pressure explosion gasesfollowing the ignition of a combustible mixture in said chambers, andwith an outlet valve for the residual combustion gases of the chambers,and nozzle and rotor blading systems arranged to receive the explosiongases discharged by said chambers, said valves being adapted to beoperated in predetermined sequence to determine the working cyclesections of the explosion chambers, the number of explosion chambersassociated with said nozzle and blading systems being at least equal tothe number of working cycle sections in each working cycle of thechambers.

15. Apparatus according to claim 14, wherein each explosion chamber isprovided with at least n+1 controlled outlet members for the combustiongases, n being a whole number at least equal to 1, said apparatusincluding a nozzle and blading system arranged to receive the residualcombustion gases discharged by the outlet valves and suited to theenergy condition of such gases, a conduit for conducting the residualcombustion gases to the last mentioned nozzle and blading system and acollecting chamber arranged to receive the explosion gases exhaustingfrom the nozzle and blading system which is impinged by the next higherpressure explosion gas portion, said conduit opening into saidcollecting chamber.

16. A driving gas generator for producing combustion gases, comprising aplurality of explosion chambers provided with compressed air and fuelcharging valves, nozzle valves for the discharge of high pressureexplosion gases following the ignition of a combustible mixture in saidchambers, and outlet valves for the residual combustion gases of thechambers, nozzle and rotor blading systems arranged to receive theexplosion gases discharged by said chambers, said valves being adaptedto be operated in predetermined sequence to determine the working cyclesections of the explosion chambers, the number of explosion chambersassociated with said nozzle and blading systems being equal to thenumber of working cycle sections in each working cycle of the chambers,said working cycle sections being of equal duration and following eachother without intervening pauses and without overlapping of suchsections, and mechanism for operating said valves.

17. A driving gas generator for producing and delivering combustiongases under pressure, comprising four explosion chambers each providedwith a compressed air charging valve and a fuel valve, two nozzle valvesfor the discharge of high pressure explosion gases following theignition of a combustible mixture in the chamber, and an outlet valvefor the residual combustion gases, two nozzle and rotor blading systemsarranged to receive the explosion gases discharged by said nozzle valvesin sequence, a third nozzle and rotor blading system provided with meansfor conducting the residual combustion gases of the chambers thereto,said valves being adapted to be operated in predetermined sequence tocause discharge of the explosion gases in two portions through the saidnozzle valves in sequence, followed by the discharge of the residualcombustion gases, and said valves operating according to a cycle whichincludes four time sections of equal duration, the operation of thevalves in the four chambers being displaced progressively by a cyclesection, and means for operating the valves.

18. Apparatus according to claim 17, wherein the three rotors are eachprovided with only a single row of blading.

19. An explosion turbine plant comprising a plurality of turbine stages,nozzles for charging explosion gases against the blading of such stages,explosion chambers for generating combustion gases by explosion underconstant volume, and combustion gas conduits disposed Within and afterthe explosion turbine stages, said conduits being constructed andarranged to conduct the gases directly from the explosion chambers tothe nozzles, and directly from one stage to the next stage Without theinterposition of heat-withdrawing apparatus.

20. Process according to claim 1, wherein the combustion chamber meanscomprises a plurality of chambers equal to the number of cycle sectionsin the working cycle of the chambers, at least two of the sections beingassigned to partial expansions of the explosion gases, said processincluding displacing the cycles of the chambers progressively by onecycle section, and maintaining said partial expansion sections ofsubstantially equal duration and the duration of each substantiallyequal to the cycle period divided by the number of explosion chambers.

References Cited in the file of this patent UNITED STATES PATENTS1,931,545 Holzwarth Oct. 24, 1933 1,933,385 Noack Oct. 31, 19331,969,753 Holzwarth Aug. 14, 1934 1,988,456 Lysholm Ian. 22, 19352,010,823 Noack Aug. 13, 1935 2,603,063 Ray July 15, 1952

